From the 1Department of Obstetrics and Gynecology, Oulu University Hospital, the 2Graduate School of Circumpolar Wellbeing, Health and Adaptation, and the 3National Institute for Health and Welfare, Oulu, Finland; and the 4National Institute for Health and Welfare and the 5Nordic School of Public Health, the Department of Obstetrics and Gynecology, Helsinki University Central Hospital, Helsinki, Finland.
Funded by Helsinki University Central Hospital (Drs. Suhonen and Heikinheimo), University Hospital of Oulu (Dr. Niinimäki), and The Finnish Cultural Foundation (Dr. Niinimäki).
The authors thank Matti Kesti for his help with computation.
Corresponding author: Dr. Oskari Heikinheimo, Dept Ob&Gyn, Helsinki University Central Hospital, P.O. Box 140, 00029-HUS, Helsinki, Finland; e-mail: [email protected].
Financial Disclosure Dr. Suhonen has lectured at meetings organized by Schering Plough (Helsinki, Finland). Dr. Heikinheimo has been a paid consultant and lecturer for Bayer Schering Pharma AG (Berlin, Germany) and for Schering-Plough (Helsinki, Finland). He also belongs to both the international and Finnish advisory boards for Bayer Schering Pharma. The other authors did not disclose any potential conflicts of interest.